Memory cell arrays

ABSTRACT

Some embodiments include memory cells. The memory cells may have a first electrode, and a trench-shaped programmable material structure over the first electrode. The trench-shape defines an opening. The programmable material may be configured to reversibly retain a conductive bridge. The memory cell may have an ion source material directly against the programmable material, and may have a second electrode within the opening defined by the trench-shaped programmable material. Some embodiments include arrays of memory cells. The arrays may have first electrically conductive lines, and trench-shaped programmable material structures over the first lines. The trench-shaped structures may define openings within them. Ion source material may be directly against the programmable material, and second electrically conductive lines may be over the ion source material and within the openings defined by the trench-shaped structures.

RELATED PATENT DATA

This patent resulted from a continuation of U.S. patent application Ser.No. 14/448,352, which was filed Jul. 31, 2014, and which is herebyincorporated herein by reference; which resulted from a continuation ofU.S. patent application Ser. No. 13/856,561, which was filed Apr. 4,2013, which issued as U.S. Pat. No. 8,822,974, and which is herebyincorporated herein by reference; which resulted from a continuation ofU.S. patent application Ser. No. 13/275,168, which was filed Oct. 17,2011, which issued as U.S. Pat. No. 8,536,561, and which is herebyincorporated herein by reference.

TECHNICAL FIELD

Memory cells and memory cell arrays.

BACKGROUND

Memory is one type of integrated circuitry, and is used in computersystems for storing data. Integrated memory is usually fabricated in oneor more arrays of individual memory cells. The memory cells areconfigured to retain or store memory in at least two differentselectable states. In a binary system, the states are considered aseither a “0” or a “1”. In other systems, at least some individual memorycells may be configured to store more than two levels or states ofinformation.

An example memory device is a programmable metallization cell (PMC).Such may be alternatively referred to as a conductive bridging RAM(CBRAM), nanobridge memory, or electrolyte memory. A PMC may use ionconductive material (for instance, a suitable chalcogenide or any ofvarious suitable oxides) sandwiched between a pair of current conductiveelectrodes, and such material may be referred to as “switching” materialor as a “programmable” material. A suitable voltage applied across theelectrodes can generate current-conductive super-ionic clusters orconducting filaments. Such may result from ion transport through the ionconductive material which grows the clusters/filaments from one of theelectrodes (the cathode) and through the ion conductive material. Theclusters or filaments create current-conductive paths between theelectrodes. An opposite voltage applied across the electrodesessentially reverses the process and thus removes the conductive paths.A PMC thus comprises a high resistance state (corresponding to the statelacking a conductive bridge extending through the switching material)and a low resistance state (corresponding to the state having theconductive bridge extending through the switching material), with suchstates being reversibly interchangeable with one another.

Although there has been some effort toward development of PMC devices,there remains a need for improved memory cells, and improved memory cellarrays. Accordingly, it would be desirable to develop new memory cellsand memory cell arrays.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are diagrammatic cross-sectional views of an exampleembodiment memory cell. The view of FIG. 1 is along the line 1-1 of FIG.2, and the view of FIG. 2 is along the line 2-2 of FIG. 1.

FIG. 3 is a diagrammatic cross-sectional view of another exampleembodiment memory cell. The view of FIG. 3 is along a similarcross-section as the view of FIG. 1.

FIGS. 4 and 5 are diagrammatic cross-sectional views of an exampleembodiment memory cell array. The view of FIG. 4 is along the line 4-4of FIG. 5, and the view of FIG. 5 is along the line 5-5 of FIG. 4.

FIGS. 6-8 are diagrammatic illustrations of various level-stackingconfigurations that may be utilized in some example embodiment memorycell arrays. The configuration of FIG. 6 encompasses the exampleembodiment memory cell array of FIGS. 4 and 5.

FIGS. 9 and 10 are diagrammatic cross-sectional views of another exampleembodiment memory cell array. The view of FIG. 9 is along the line 9-9of FIG. 10, and the view of FIG. 10 is along the line 10-10 of FIG. 9.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Some embodiments include new memory cell architectures. The memory cellsmay be PMC devices in which programmable material is formed inupwardly-opening trench shapes. Additional structures of the PMC devices(for instance, an electrode and/or an ion source material) may be formedto extend within the openings in the trench shapes. Such may enable PMCdevices to be formed with fewer masking steps than are utilized inconventional processing. Further, the PMC devices may be relativelycompact compared to conventional memory cells in that some components ofthe devices are nested within the trench-shaped programmable material.This may enable the PMC devices described herein to be utilized inhighly integrated circuitry such as, for example, memory arrays.

Example embodiments are described with reference to FIGS. 1-10.

Referring to FIGS. 1 and 2, an example memory cell 12 is shown as partof a semiconductor construction 10. The semiconductor constructionincludes a semiconductor base 12 having a dielectric material 14thereover, and having an electrically conductive line 16 over thedielectric material 14.

In some embodiments, base 12 may comprise semiconductor material. Forinstance, base 12 may comprise, consist essentially of, or consist ofmonocrystalline silicon. In such embodiments, the base may be referredto as a semiconductor substrate, or as a portion of a semiconductorsubstrate. The terms “semiconductive substrate,” “semiconductorconstruction” and “semiconductor substrate” mean any constructioncomprising semiconductive material, including, but not limited to, bulksemiconductive materials such as a semiconductive wafer (either alone orin assemblies comprising other materials), and semiconductive materiallayers (either alone or in assemblies comprising other materials). Theterm “substrate” refers to any supporting structure, including, but notlimited to, the semiconductive substrates described above. Although base12 is shown to be homogenous, the base may comprise numerous materialsin some embodiments. For instance, base 12 may correspond to asemiconductor substrate containing one or more materials associated withintegrated circuit fabrication. In such embodiments, such materials maycorrespond to one or more of refractory metal materials, barriermaterials, diffusion materials, insulator materials, etc; and/or mayinclude additional integrated circuitry, such as, for example,transistor access devices.

The dielectric material 14 may comprise any suitable composition orcombination of compositions; and in some embodiments may comprise,consist essentially of, or consist of silicon oxide.

The electrically conductive line 16 extends along an axis 5 parallel tothe cross-section of FIG. 1, and orthogonal to the cross-section of FIG.2. In the shown embodiment, the conductive line 16 comprises a barrier17 that extends along the sidewalls and bottom of the line, a core 19over the barrier 17, and another barrier 21 over the core 19. The core19 may comprise any suitable material, and in some embodiments maycomprise, consist essentially of, or consist of copper. The barrierlayers 17 and 21 may be barriers to copper migration, and may compriseany suitable materials. For instance, the barrier layers 17 and 21 maycomprise one or more of cobalt, tantalum and ruthenium. In someembodiments, one or both of the barrier layers may comprise a mixture ofcobalt, tungsten and phosphorus. In some embodiments, the core 19 maycomprise an electrically conductive material which does not havemigratory constituents (for instance, the core may consist of metalother than copper; such as, for example, tungsten, titanium, platinum,etc.), and in such embodiments the barrier layers 17 and 21 may beomitted.

The electrically conductive line 16 comprises a region 18 whichcorresponds to an electrode of the memory cell 12. The conductive lineis an example of a wiring component which may be electrically coupledwith the electrode of the memory cell. In other embodiments, otherwiring components may be utilized alternatively, or in addition to, theconductive line. Further, although the conductive line is shownencompassing the electrode 18, in other embodiments the electrode may bespaced from the line by another electrical component; such as, forexample, a select device (for instance, a diode or an ovonic thresholdswitch).

A dielectric material 20 is along sidewalls of the conductive line 16,as shown in FIG. 2. The dielectric material 20 may comprise any suitablecomposition, and in some embodiments may comprise silicon dioxide. Thedielectric material 20 may be the same composition as the dielectricmaterial 14 in some embodiments, and may be a different composition fromdielectric material 14 in other embodiments. The conductive line 16 maybe formed to extend within dielectric material 20 by, for example,conventional damascene processing or other known methods.

A programmable material 22 is over the electrode 18. The programmablematerial is trench-shaped (as shown in FIG. 1), and has an opening 23defined therein. In the embodiment of FIGS. 1 and 2, the trench-shapedprogrammable material 22 forms a trough that extends along a directionof an axis 7 shown in FIG. 2. Such trough extends orthogonally to thedirection of axis 5 (FIG. 1); or in other words orthogonally to the line16.

An ion source material 24 is within the opening 23 defined by thetrench-shaped material 22. The ion source material is directly againstthe programmable material 22. In the shown embodiment, the ion sourcematerial only partially fills opening 23 to leave a remaining portion ofthe opening over the ion source material.

An electrically conductive line 26 is over the ion source material andwithin the opening 23.

In the shown embodiment, the electrically conductive line 26 comprisesan electrically conductive barrier 27 that extends along the sidewallsand bottom of the line, a core 29 over the barrier 27, and anotherbarrier 31 over the core 29. The core 29 may comprise any suitablematerial, and in some embodiments may comprise, consist essentially of,or consist of copper. The barrier layers 27 and 31 may be barriers tocopper migration and/or barriers to the ion source material, and maycomprise any suitable materials. For instance, the barrier layers 27 and31 may comprise one or more of cobalt, tantalum and ruthenium. In someembodiments, one or both of the barrier layers may comprise a mixture ofcobalt, tungsten and phosphorus. In some embodiments, the core 29 maycomprise an electrically conductive material which does not havemigratory constituents (for instance, the core may consist of materialother than copper), and in such embodiments the barrier layers 27 and 31may be omitted.

The electrically conductive line 26 comprises a region 28 whichcorresponds to an electrode of the memory cell 12. The electrodes 18 and28 may be referred to as first and second electrodes, respectively, insome embodiments. Although the electrode 28 is shown being encompassedby the line 26, in other embodiments the electrode may be spaced fromthe line 26 by another electrical component; such as, for example, aselect device (for instance, a diode or an ovonic threshold switch).

Electrode 18 may comprise an electrochemically active surface againstthe adjacent programmable material 22. Any suitable electrochemicallyactive materials may be utilized along said surface, such as, forexample, copper, silver, alloys including at least one of copper andsilver, etc. In contrast, the electrode 28 may comprise anelectrochemically inactive surface against the ion source material 24.The electrochemically inactive surface may comprise any suitableelectrically conductive compositions or combinations of compositions,and may, for example, comprise, consist essentially of, or consist ofone or more of various metals (for instance, titanium, tantalum,ruthenium, tungsten, platinum, mixed metal alloys, etc.) andmetal-containing compounds (for instance, metal nitride, metal carbide,metal silicide, etc.).

The programmable material 22 may be a solid, gel, or any other suitablephase, and may comprise chalcogenide-type materials (for instance,materials comprising germanium in combination with one or more ofantimony, tellurium, sulfur and selenium), oxides (for instance,zirconium oxide, titanium oxide, hafnium oxide, aluminum oxide, tungstenoxide, silicon oxide, etc.) and/or any other suitable materials. Theprogrammable material reversibly retains at least one conductive bridgebetween electrode 18 and ion source material 24 during operation of thememory cell. Specifically, the programmable material may be reversiblyswitched between a high resistance state and a low resistance state toprogram the memory cell. The programmable material is in the lowresistance state when the conductive bridge is retained within theprogrammable material, and is in the high resistance state when theconductive bridge is not continuous across the programmable material.The conductive bridge may be formed by providing a suitable electricfield of a first polarity between the electrodes 18 and 28 to cause ionmigration from ion source material 24 into the programmable material 22to thereby create one or more filaments corresponding to such conductivebridge. The conductive bridge may be removed by providing an electricfield of a second polarity, opposite to the first polarity, between theelectrodes 18 and 28 such that material of the conductive bridge isdispersed to effectively dissolve such conductive bridge.

The ion source material 24 contributes the ions which ultimately formthe conductive bridge across the programmable material 22. The ionsource material may comprise any suitable composition or combination ofcompositions; and in some embodiments will comprise one or both ofcopper and silver, and thus may be configured for contributing coppercations and/or silver cations for formation of the conductive bridge.For instance, the ion source material may comprise a combination ofcopper and tellurium. The ion source material is electricallyconductive, but is not shown with cross-hatching in FIGS. 1 and 2 inorder to simplify the drawings.

In the embodiment of FIGS. 1 and 2, both the ion source material 24 andthe second electrode 28 are entirely contained within the opening in thetrench-shaped structure of programmable material 22. In otherembodiments, the ion source material may not be within such opening (forexample, FIG. 3 shows an embodiment in which the ion source material isnot within the opening in the trench-shaped structure of theprogrammable material), or the top electrode may not be within suchopening (for instance, in some embodiments the ion source material mayentirely fill the opening within the trench-shaped structure of theprogrammable material).

The construction 10 comprises a dielectric material 34 along the outersidewalls of the trench-shape of the programmable material 22. Thedielectric material 34 is configured as liners along such sidewalls. Insome embodiments, the dielectric material may comprise high k material;and may, for example, comprise, consist essentially of, or consist ofsilicon nitride. A “high k” dielectric material is any dielectricmaterial having a dielectric constant greater than 3.9, or in otherwords, having a dielectric constant greater than that of silicondioxide.

The dielectric material 34 may form a lateral barrier along the memorycell, and may be a barrier to preclude migration of components of thememory cell laterally outward of the memory cell. For instance, thedielectric material 34 may be a barrier relative to migration oftellurium and/or copper in embodiments in which the ion source material24 comprises the combination of copper and tellurium. In someembodiments, the materials 17, 21, 27 and 31 may be considered to beelectrically conductive barrier materials, and the material 34 may beconsidered to be an electrically insulative barrier material. Regions ofthe memory cell are encapsulated by the electrically conductive andelectrically insulative barrier materials; and such regions may bethereby protected from having components migrate out of the them, and/orfrom having components migrate into them.

Another dielectric material 36 is provided laterally outwardly of thedielectric material 34. In some embodiments, dielectric material 36 maycomprise a low k material (with “low k” dielectric materials beingdielectric materials having dielectric constants less than or equal tothat of silicon dioxide); and may, for example, comprise one or more ofsilicon dioxide, vacuum and gas. For instance, the dielectric material36 may comprise porous silicon dioxide, and/or may correspond to a gapbetween adjacent liners of material 34.

Although the construction 10 is shown to comprise the low k dielectricmaterial 36 utilized in combination with the high k dielectric material34, in some embodiments the low k material 36 may be omitted andreplaced with additional high k dielectric material 34, or vice versa.

The embodiment of FIGS. 1 and 2 has the ion source material 24 betweenthe programmable material 22 and the second electrode 28. In otherembodiments, the ion source material may be provided between theprogrammable material and the first electrode. FIG. 3 shows aconstruction 10 a illustrating an example embodiment memory cell 12 a inwhich the programmable material is between the ion source material andthe first electrode. Similar numbering will be utilized to describe theembodiment of FIG. 3 as is used above to describe the embodiment ofFIGS. 1 and 2, where appropriate.

The construction 10 a has ion source material 24 provided at the bottomof an opening between the liners of material 34, and directly against anupper surface of the bottom electrode 18. The trench-shaped structure ofprogrammable material 22 is formed over and directly against the ionsource material 24, and the upper electrode 28 is formed within theopening in the trench-shaped structure.

The embodiment of FIG. 3 may comprise an electrochemically activesurface of electrode 28 directly against the programmable material 22,and may comprise an electrochemically inactive surface of electrode 18directly against the ion source material 24. Thus, the electrochemicalactivity of electrodes 18 and 28 may be reversed in the embodiment ofFIG. 3 relative to the embodiment of FIGS. 1 and 2.

FIGS. 4 and 5 illustrate a construction 50 comprising an exampleembodiment array of memory cells. Similar numbering will be utilized todescribe the embodiment of FIGS. 4 and 5 as is used above to describethe embodiments of FIGS. 1-3, where appropriate.

The construction 50 comprises a plurality of memory cells 52 arranged inthree different levels L₁-L₃. The memory cells within level L₁ arelabeled as cells 52 ₁, those within level L₂ are labeled as cells 52 ₂,and those within level L₃ are labeled as cells 52 ₃. The illustratedmemory cells are analogous to the cell 12 a of FIG. 3. In otherembodiments, cells analogous to the cell 12 of FIGS. 1 and 2 may beutilized.

Each level comprises a pair of conductive lines 16 and 26. Theconductive lines are shared between adjacent levels in the illustratedembodiment, and thus there are only four conductive lines even thoughthere are three levels. The lowest lines are labeled 16 ₁, and comprisebottom electrodes for the memory cells 52 ₁. The lines of the next levelare labeled 26 ₁ and comprise top electrodes for the memory cells 52 ₁and bottom electrodes for the memory cells 52 ₂. The lines of the nextlevel are labeled 16 ₂ and comprise top electrodes for the memory cells52 ₂ and bottom electrodes for the memory cells 52 ₃. Finally, the linesof the top level are labeled 26 ₂ and comprise top electrodes for thememory cells 52 ₃.

The alternating labels 16 and 26 are utilized to assist in describingthe arrangement of the lines relative to the memory cells, and not toindicate compositional differences between lines labeled 16 and thoselabeled 26. The lines 26 are shown comprising materials 27, 29 and 31 tobe consistent with FIGS. 1-3, and the lines 16 are shown comprisingmaterials 17, 19 and 21 to be consistent with such figures. However, asdiscussed above with reference to FIGS. 1-3, materials 27, 29 and 31 maybe identical to materials 17, 19 and 21. Thus, lines labeled 16 may becompositionally identical to those labeled 26 in some embodiments. Thelines 16 extend along a first direction, and the lines 26 extend along asecond direction that intersects the first direction so that the lines26 overlap the lines 16. The memory cells 52 are formed at cross-pointswhere the lines 26 overlap the lines 16.

In the shown embodiment, the programmable material 22 of the memorycells 52 is configured as trench-shaped structures that extendsubstantially orthogonally to the lines 16, and the lines 26 areentirely contained within openings in such trench-shaped structures. Thememory cells 52 comprise regions of the programmable material 22 and theion source 24 that are directly between overlapping segments of lines 16and 26.

In the shown embodiment, the ion source material 24 forms a plurality oflines that are directly under the trench-shaped structures containingthe programmable material 22, and coextensive with such trench-shapedstructures.

Structures comprising dielectric material 34 are adjacent the memorycells 52, and are entirely along sides of the lines of the ion sourcematerial 24 in the shown embodiment. Such structures may be referred toas liners. In the shown embodiment, the low k dielectric material 36 isprovided between adjacent liners of the dielectric material 34. Asdiscussed previously, in some embodiments the dielectric material 34 maycomprise high k dielectric material (such as silicon nitride), and thelow k dielectric material may comprise one or both of silicon dioxideand gas. In some embodiments, the low k dielectric material 36 may beomitted and the high k dielectric material 34 may extend entirely acrossthe gaps between adjacent memory cells, or vice versa.

A lower line 16 ₁ is shown to be electrically coupled to externalcircuitry 56 through a conductive interconnect 54. The conductiveinterconnect may comprise any suitable material, and in some embodimentsmay comprise a metal, such as, for example, tungsten. The externalcircuitry 56 may be utilized for reading from and/or writing to thememory cells adjacent the line 16 ₁. The other lines 16 ₂, 26 ₁, and 26₂ may be electrically connected to similar circuitry. In operation, eachof the individual memory cells may be uniquely addressed through pairedcombinations of the conductive lines.

The illustrated levels L₁-L₃ represent multiple vertical levels, ortiers, of a memory array. Each vertical level may be considered to havea bottom below the upwardly opening trench structure of the programmablematerial 22, and to have a top in opposing relation to the bottom. Thetops of the levels L₁-L₃ are labeled as T₁-T₃, and the bottoms of suchlevels are labeled as B₁-B₃. The terms “bottom” and “top” are used todefine an orientation of a memory cell relative to the trench-shapedprogrammable material of the memory cell, and provide terminology forcomparing vertical orientations of the various levels of a memory array.The “bottom” of a memory cell is the portion of the memory cell adjacentthe closed end of the trench-shaped programmable material, and the “top”is the portion of the memory cell adjacent the open end of such trench.As will become clear from the discussion that follows, memory cells maybe sometimes be arranged with the “bottom” below the “top”, and may besometimes arranged with the “bottom” above the “top”.

Each of the levels L₁-L₃ has a vertical arrangement between the “tops”and “bottoms” of the memory cells contained therein, with such verticalarrangements being shown with arrows extending from the bottoms to thetops of the levels (e.g., the arrow extending from B₁ to T₁). In theshown embodiment, each level has the same vertical arrangement as theothers (specifically, the “top” of each level is vertically above the“bottom”). FIGS. 6-8 diagrammatically illustrate some exampleembodiments of vertical arrangements of levels within memory arrays thatmay be utilized in some embodiments.

FIG. 6 shows the same vertical arrangement as is present in theembodiment of FIGS. 4 and 5. Notably, all of the levels are oriented inthe same direction, with the “top” over the “bottom”, and the levelsvertically overlap so that the “bottom” of a level overlaps the “top” ofthe level immediately below it.

FIG. 7 shows an embodiment similar to that of FIG. 6, except thatvertical memory cell levels are spaced from one another by insulativelevels (I₁ and I₂), and thus the memory cell levels do not verticallyoverlap one another. The insulative levels may comprise any suitabledielectric material, and in some embodiments may comprise silicondioxide.

FIG. 8 shows an embodiment in which the vertical memory cell levels arespaced from one another by insulative levels (I₁ and I₂), and in whichsome of the memory cell levels are inverted relative to others(specifically, memory cell levels L₁ and L₃ are arranged with the “top”above the “bottom,” and memory cell level L₂ is arranged with the“bottom” above the “top”). Although FIG. 8 shows insulative levels I₁and I₂ between the various memory cell levels, in other embodiments suchinsulative levels may be omitted.

FIGS. 9 and 10 illustrate a construction 80 comprising another exampleembodiment array of memory cells.

The construction 80 comprises a plurality of memory cells 82. Theillustrated memory cells are analogous to the cell 12 of FIGS. 1 and 2.In other embodiments, cells analogous to the cell 12 a of FIG. 3 may beutilized.

The memory cells comprise trench-shaped structures of programmablematerial 22, and comprise ion source material 24 within openings definedby the trench shapes. The trench-shaped structures form a plurality ofspaced-apart pedestals 84 that extend between a lower conductive line 16and an upper conductive line 26. The ion source material 24 is entirelycontained within the spaced-apart pedestals.

In the shown embodiment, the dielectric material 36 is entirely alonglateral peripheries of the pedestals 84. The dielectric material 36(FIGS. 4 and 5) is omitted from the embodiment of FIGS. 9 and 10 so thatthe dielectric material 34 extends entirely across gaps between adjacentpedestals 84. In other embodiments, dielectric material 36 could beincluded in regions between adjacent dielectric material linersanalogously to the embodiment discussed above with reference to FIGS. 4and 5.

The memory cells and arrays discussed above may be incorporated intoelectronic systems. Such electronic systems may be used in, for example,memory modules, device drivers, power modules, communication modems,processor modules, and application-specific modules, and may includemultilayer, multichip modules. The electronic systems may be any of abroad range of systems, such as, for example, clocks, televisions, cellphones, personal computers, automobiles, industrial control systems,aircraft, etc.

The particular orientation of the various embodiments in the drawings isfor illustrative purposes only, and the embodiments may be rotatedrelative to the shown orientations in some applications. The descriptionprovided herein, and the claims that follow, pertain to any structuresthat have the described relationships between various features,regardless of whether the structures are in the particular orientationof the drawings, or are rotated relative to such orientation.

The cross-sectional views of the accompanying illustrations only showfeatures within the planes of the cross-sections, and do not showmaterials behind the planes of the cross-sections in order to simplifythe drawings.

When a structure is referred to above as being “on” or “against” anotherstructure, it can be directly on the other structure or interveningstructures may also be present. In contrast, when a structure isreferred to as being “directly on” or “directly against” anotherstructure, there are no intervening structures present. When a structureis referred to as being “connected” or “coupled” to another structure,it can be directly connected or coupled to the other structure, orintervening structures may be present. In contrast, when a structure isreferred to as being “directly connected” or “directly coupled” toanother structure, there are no intervening structures present.

In some embodiments, a memory cell comprises a first electrode and atrench-shaped programmable material structure over the first electrode.The trench-shape defines an opening therein. The programmable materialis configured to reversibly retain a conductive bridge. The memory cellis in a low resistive state when the conductive bridge is retainedwithin the programmable material and is in a high resistive state whenthe conductive bridge is not within the programmable material. An ionsource material is directly against the programmable material. A secondelectrode extends into the opening defined by the trench-shapedprogrammable material.

In some embodiments, a memory cell comprises a first electrode and atrench-shaped programmable material structure over the first electrode.The trench-shape defines an opening therein. The programmable materialis configured to reversibly retain a conductive bridge. The memory cellis in a low resistive state when the conductive bridge is retainedwithin the programmable material and is in a high resistive state whenthe conductive bridge is not within the programmable material. An ionsource material is entirely contained within the opening defined by thetrench-shaped programmable material structure. A second electrode isover the ion source material.

In some embodiments, an array of memory cells comprises a firstelectrically conductive line extending along a first direction, and aplurality of trench-shaped programmable material structures over thefirst line. The trench-shaped structures extend along a second directionwhich intersects the first direction. The individual trench-shapedstructures have openings defined therein. The programmable material isconfigured to reversibly retain conductive bridges within individualmemory cells to transition the memory cells between low and highresistive states. Ion source material is comprised by the individualmemory cells and is directly against the programmable material. Secondelectrically conductive lines extend into the openings defined by thetrench-shaped programmable material structures. Individual memory cellscomprise regions of programmable material and ion source materialdirectly between the first and second lines.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

We claim:
 1. An array of memory cells, comprising: trench-shapedprogrammable material structures over a first conductive line; secondconductive lines that extend into trenches of the trench-shapedprogrammable material structures; regions of programmable materialbetween the first and second conductive lines being comprised by memorydevices; the first and second conductive lines, and the programmablematerial between the first and second conductive lines, together forminga first level of the array; said first level having a verticalarrangement from the first conductive line to the second conductivelines; and a second level of the array over the first level, said secondlevel having the same vertical arrangement as the first level.
 2. Thearray of claim 1 further comprising a material containing copper withinthe trenches of the trench-shaped programmable material structures, andbetween the second conductive lines and the regions of programmablematerial.
 3. The array of claim 1 further comprising a materialcontaining copper between the first conductive line and thetrench-shaped programmable material structures.
 4. The array of claim 1further comprising a material containing silver within the trenches ofthe trench-shaped programmable material structures, and between thesecond conductive lines and the regions of programmable material.
 5. Thearray of claim 1 further comprising a material containing silver betweenthe first conductive line and the trench-shaped programmable materialstructures.
 6. The array of claim 1 further comprising a materialcontaining copper and tellurium within the trenches of the trench-shapedprogrammable material structures, and between the second conductivelines and the regions of programmable material.
 7. The array of claim 1further comprising a material containing copper and tellurium betweenthe first conductive line and the trench-shaped programmable materialstructures.
 8. An array of memory cells, comprising: a plurality oftrench-shaped programmable material structures over a first conductiveline; second conductive lines that extend into trenches within thetrench-shaped programmable material structures; regions of programmablematerial between the first and second conductive lines being comprisedby memory devices; the first and second conductive lines, and theprogrammable between the first and second conductive lines, togetherforming a first level of the array; said first level having a verticalarrangement from the first conductive line to the second conductivelines; and a second level of the array over the first level; said secondlevel having an opposite vertical arrangement relative to the firstlevel.
 9. The array of claim 8 further comprising a material containingcopper within the trenches of the trench-shaped programmable materialstructures, and between the second conductive lines and the regions ofprogrammable material.
 10. The array of claim 8 further comprising amaterial containing copper between the first conductive line and thetrench-shaped programmable material structures.
 11. The array of claim 8further comprising a material containing silver within the trenches ofthe trench-shaped programmable material structures, and between thesecond conductive lines and the regions of programmable material. 12.The array of claim 8 further comprising a material containing silverbetween the first conductive line and the trench-shaped programmablematerial structures.
 13. The array of claim 8 further comprising amaterial containing copper and tellurium within the trenches of thetrench-shaped programmable material structures, and between the secondconductive lines and the regions of programmable material.
 14. The arrayof claim 8 further comprising a material containing copper and telluriumbetween the first conductive line and the trench-shaped programmablematerial structures.
 15. An array of memory cells, comprising: a firstconductive line extending along a first direction; a plurality ofupwardly-opening-container-shaped programmable material structures overthe first conductive line; the programmable material structuresextending along a second direction which intersects the first direction;a tellurium-containing material directly against the programmablematerial structures; second conductive lines that extend into openingsof the upwardly-opening-container-shaped programmable materialstructures; memory cells comprising regions of the programmable materialbetween the first and second conductive lines; individual memory cellscomprising a conductive bridge within the programmable material in amemory state; wherein the tellurium-containing material is between thefirst conductive line and the programmable material structures; andwherein the tellurium-containing material is configured as linescoextensive with the programmable material structures.
 16. The array ofclaim 15 further comprising dielectric liners entirely along sides ofthe tellurium-containing material lines.
 17. The array of claim 15wherein the tellurium-containing material also contains copper.